JPH0448698A - Electronic component mounting device - Google Patents

Abstract

PURPOSE:To obtain an accurate positioning without giving a shock to electronic components or other devices when mounting the electronic components by computing the amount of warp of the substrate surface detected by a noncontact measuring device and the height of the component for controlling the down stroke of a suction nozzle so that the bottom of the component is situated on the specified location of the substrate surface. CONSTITUTION:A chip placer 1 is equipped with a plurality of suction nozzles 2, a noncontact sensor 11 which is located above an X-Y table 5 to detect the amount of warp of a substrate K, and a nozzle stroke variable actuator 12 which controls tire nozzle stroke of the suction nozzle 2 in the X-axis direction based on the information obtained from the noncontact sensor 11. The whole surface of the substrate K is measured for warp by moving the X-Y table 5 in the X and the Y directions. Signals from the sensor 11 are sent to a measuring unit 14 to be stored as NC data. The amount of warp of the substrate K is calculated based on the NC data. The nozzle stroke variable actuator 12 corrects the amount of movement of the suction nozzle 2 in the Z-axis direction according to the amount of warp of the substrate K measured by the sensor 11 when components are mounted onto the substrate K by the suction nozzle 2.

Description

DETAILED DESCRIPTION OF THE INVENTION A. Field of Industrial Application The present invention relates to an electronic component mounting device that mounts electronic components by suctioning them with a suction nozzle, and provides reliable positioning without applying a load to the board and the components to be mounted. This design allows electronic components to be mounted on the board.

B8 Summary of the Invention The present invention measures the amount of warpage on the board surface of a board being transferred to a component mounting position using a non-contact measuring device, and calculates the amount of warpage and the height of the part to be mounted, thereby determining a predetermined amount of warpage on the board surface. The downward stroke of the suction nozzle is controlled so that the bottom surface of the component is located at the position shown in FIG.

C1 Prior Art Conventionally, electronic component mounting devices such as chimp bracers have been known as devices for automatically mounting surface-mounted electronic components on circuit boards and the like. This chimp placer is generally known to pick up a component supplied from a bar center by suction with a suction nozzle, and mount it at a predetermined position on a circuit board.

By the way, if the board on which the electronic component is mounted has warpage or distortion, there is a problem that the electronic component cannot be mounted at the correct position on the board by the suction nozzle. Particularly now that the packaging density of circuit boards has increased, mounting electronic components in accurate positions is an important issue.

Therefore, in the past, in order to mount electronic components in response to warpage and distortion of the board, a spring 51 is fitted to the tip of the suction nozzle 50, as shown in FIG. It has been proposed that the electronic component T is mounted on the board by moving up and down in accordance with the warpage of the board to absorb the warpage of the board.

D0 Problem to be Solved by the Invention However, according to the above means, the electronic component T to be attached is
This will cause extra pressure to be applied.

Therefore, if there is a large warp or the like, there is a risk that the attached parts will be subjected to impact and the electronic component T itself will be cracked or chipped. Also, the side of the board may be damaged.

Furthermore, there is also the problem that vibrations occur in the board K during attachment, causing the already attached components to become misaligned.

Therefore, as a means to solve the above problem, the substrate K is housed in a substrate holder 60 as shown in FIG. A method has been proposed for mounting the electronic component T on the surface of the substrate by correcting it. According to this means, it is possible to certainly eliminate warpage and the like on the board and to mount electronic components at an accurate position on the board surface without applying any extra load.

However, in the case of this means, a suction jig 61 suitable for each substrate is required to reliably suction the substrate K within the substrate holder 60. Therefore, it is disadvantageous in terms of versatility and cost, and is difficult to be adopted in reality.Also, the substrate itself cannot have a complicated structure in order to ensure reliable suction to the substrate by this suction jig 61. There are also major restrictions on board design.

Therefore, the present invention measures the warpage, etc. of the board itself in advance with a non-contact measuring device, calculates the amount of warpage and the height of the component to be mounted, and uses the suction nozzle to position the bottom of the component at a predetermined position on the surface of the board. By controlling the descending stroke of
The electronic component can be mounted on the surface of the board without applying any impact to the electronic component during mounting, and with reliable positioning.

89 Means for Solving the Problems In order to achieve the above-mentioned problems, an electronic component mounting apparatus according to the present invention includes a board transfer means for transporting a board to a component mounting position;
A non-contact measuring device is used to measure the amount of warpage over the entire area of the board that is driven and held by the measuring device drive holding means and transferred to the component mounting position. It has a suction nozzle that moves to a predetermined position,
The above non-contact measuring device detects the amount of warpage on the substrate surface,
The present invention is characterized in that the descending stroke of the suction nozzle is controlled so that the bottom surface of the component is located at a predetermined position on the surface of the substrate by calculating the amount of warpage and the height of the component.

F2 action According to the present invention, the amount of warpage on the board surface is detected by a non-contact measuring device when the board is transferred to the component mounting position, and the amount of warp and the height of the part to be mounted are calculated. The descending stroke of the suction nozzle is controlled so that the bottom surface of the component is positioned at , and the electronic component is attached to the substrate surface by the suction nozzle.

G. EXAMPLES Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a schematic external view of a so-called chip placer, which is an electronic component mounting device to which the present invention is applied. This chip placer 1 includes a rotary head 3 provided with a plurality of suction nozzles 2, a component supply section 4 that supplies components to the suction nozzles 2, a substrate K fixed thereon, and a component mounting location placed between the suction nozzles 2 and a substrate K. X-Y perpendicular to each other for the parts of
An X-Y table 5 that performs positioning operation in the direction, and a video camera 6 that detects the positional deviation of the suction of the component before the suction nozzle 2 mounts the suction nozzle 2. It is equipped with four actuators 7.8 and 9.10 for rotation. Further, a non-contact type sensor 11 is provided above the X-Y table 5 to detect the amount of warpage of the substrate, and the nozzle stroke of the suction nozzle 2 in the Z-axis direction is determined based on the information from this sensor 11. A variable nozzle stroke actuator 12 is provided for constant adjustment.

In the rotary head 3, a plurality of suction nozzles 2 are arranged movably up and down at equal intervals on the periphery of a base 3a on a circular plate, and each suction nozzle is moved to a station where the suction nozzles 2 are stopped by a base drive unit 3b. 2 are sequentially incremented.

The component supply unit 4 is equipped with a plurality of parts cassettes 13 that store taped electronic components T depending on the type of electronic component to be mounted, and is equipped with a Z-axis circumferential DC servo motor 4a equipped with an encoder. A predetermined parts cassette 13 is positioned so as to be able to supply parts to a station where suction is to be performed. The encoder of the DC servo motor 4a is used for servo control for its positioning.

The X-Y table 5 has a table 5b positioned in the X direction by an X-axis circumferential DC servo motor 5a, and a table 5d positioned in the X direction by a Y-axis circumferential DC servo motor 5C.
It is positioned in the direction.

The board on which the electronic component T is mounted is fixed on a table 5b with suitable fixing means such as a board holder, and the X-Y table 5 moves the board to the mounting station in the rotary head 3. The mounting location of a predetermined component is moved.

Next, the four actuators 7.8, 9.10 are fixed corresponding to predetermined stations on the rotary head 3. The θ rotation actuator 7 is provided corresponding to the station after the station where suction is performed, and rotates the direction of the suction nozzle 2 that has been advanced to that station by θ angle, so that the suctioned parts are placed on the substrate in a predetermined position. Orientation: The Δθ rotation actuator 8 is a station before mounting the video camera 6.
The station is provided corresponding to the station after the station where detection of suction deviation is performed. This actuator 8
The suction nozzle is rotated by an angular deviation Δθ in the nozzle direction (θ direction) out of the detected suction deviation of the component, and the direction of the component is corrected.

The -(θ+Δθ) rotation actuator 9 is provided corresponding to the station after mounting, and is used to return the direction of the suction nozzle 2 to its origin (initial state). The suction direction setting actuator 10 is provided after the above-mentioned station and corresponding to the stage gin before component suction. This actuator 10 is for setting the direction of the suction nozzle when picking up parts from a predetermined parts cassette 13. Each actuator 7~IO
are levers 7a to 10a (
10a (not shown) is adapted to abut on the rotating shaft of the suction nozzle 2 and rotate it at the station.

Next, a non-contact type sensor 11 is provided above the XY table 5. This non-contact sensor 1
1 is for measuring the amount of warpage on the substrate. That is, by moving the X-Y table 5 in the X-Y direction perpendicular to the sensor 11 as shown in FIGS. 3A and 3B, it is possible to measure the entire area of the board. There is. The signal detected by this sensor 11 is sent to the length measuring unit 14, where it is stored as NC data and the amount of warpage of the substrate in the Z-axis direction is measured.

The variable nozzle stroke actuator 12 is for correcting the amount of movement of the suction nozzle 2 in the Z-axis direction when the suction nozzle 2 attaches a component to the board according to the amount of warpage on the board measured by the sensor 11. It is.

FIG. 2 is a block diagram showing the configuration of the control circuit of the chip placer 1. As shown in FIG.

This control circuit includes a CPU (Central Processing Unit) 15 that controls each driving section of the chip placer, and a memory that is connected to the bus of this CPU 15 and stores programs indicating the above-mentioned control procedures and data necessary for the control. It has 16. This memory 16 contains the biting direction setting actuator 1.
The direction and height position of the suction nozzle 2 when picking up the parts No. 4 are stored in advance for each part to be picked up. The CPU 5 also includes drive units 17a and 17b.

17c, respectively connected to the Z-axis circumferential DC servo motor 4
a, the X-axis circumferential DC servo motor 5a and the Y-axis circumferential DC servo motor 5C are servo-controlled based on control amounts given from the CPU 15. moreover,
CPUI 5 has drive units 18a, 18b, 18
c, 18d, and 18e. This drive unit】8a.

18b, 18c, and 18d are respectively θ rotation actuators 766 rotation actuators 8 (θ+Δθ) rotation actuators 9. Actuator 10 for setting suction direction
The rotation angle is controlled based on the angle control value given from the CPUI 5. The drive unit 18e controls the vertical movement of the suction nozzle 2 based on the height position control value given to the variable nozzle stroke actuator 12 by the CPU 16.

The drive unit 19 controls the movement of the base drive unit 3b based on instructions from the CPU 15. In order to detect deviations in component suction by the suction nozzle 2, the pattern recognition unit 20 performs pattern recognition on the video signal of the video camera 6 to detect deviation amounts (X', Y', Δθ), and sends the detected deviation amounts to the CPU 15. It is something. The CPU 15 corrects Δθ out of this amount of deviation using the Δθ rotation actuator 10, and simultaneously corrects the amounts x' and y' of deviations when positioning the substrate mounting location.

Further, in order to measure the amount of warpage on the board, the length measuring unit 14 uses the information obtained by the sensor 11 as NC data to detect the amount of warpage (ΔL) on the board, and CPt, 1
15. The CPU 15 calculates the warp amount Δ
The descending stroke of the suction nozzle 2 is determined by calculating L and the height of the attachment part programmed in advance.

And the nozzle stroke variable actuator 12
As shown in FIG. 4, the downward stroke of the suction nozzle 2 is corrected so that the bottom of the component is located at a predetermined position on the substrate surface during mounting.

Next, the component mounting process using this apparatus will be explained below according to the above-mentioned stations. FIG. 5 is a plan view showing the stage, and each station S to S1° corresponds to the number and arrangement of the suction nozzles 2 of the low-client 3.

S. (Measurement of the amount of warpage of the board) First, when the board K has been transferred from the previous process to the electronic component mounting position, the sensor 11 detects 1. The amount of warpage of the substrate mounted in the substrate holder 21 is measured. At this time, the X-Y table 5 is driven to measure the amount of warpage ΔL at the board mounting position of the pre-programmed component. Incidentally, the sensor 11 may perform rough measurement over the entire surface of the substrate. In this case, it is sufficient to measure the amount of warpage of the entire substrate.

Then, the information measured by the sensor 11 is converted into NC data by the length measuring unit 14 and recorded in the memory 16.

S, (Suction) The taped parts set in the parts cassette 13 are sucked by the suction nozzle 2.

S3 (θ rotation) According to a predetermined program input in advance, the suction nozzle 2 is rotated so that the electronic component T is mounted on the board in a predetermined direction. The suction nozzle 2 is rotated by being powered by a θ rotation actuator tough.

S, (Camera) The video camera 6 detects the amount (X', Y', θ directions) of the component sucked by the suction nozzle 2 at a predetermined position.

Ss (Δθ rotation) The rotational deviation in the θ direction detected in S4 is corrected.

S. (Mount) The X-Y table 5 moves according to a pre-input program so that the component T picked up by the suction nozzle 2 is mounted at a predetermined position on the substrate.

Then it will be mounted. During this mounting, the variable nozzle stroke actuator 12 adjusts the descending stroke of the suction nozzle 2 by calculating the amount of warpage ΔL measured by the amount of warpage on the board and the pre-programmed mounting part height, and the The bottom surface of the component is positioned at a predetermined height position, and the component position deviation in the χ-Y direction detected in S4 is corrected to the position at which the It is corrected by

St ((θ+Δθ) rotation) Return the rotation direction of the suction nozzle to the original origin (initial state B).

Ss (Setting suction direction) The component suction direction of the suction nozzle 2 is set according to the component to be suctioned according to a pre-input program.

As described above, the present invention varies the descending stroke of the suction nozzle 2 in accordance with the amount of warpage on the board, so that the electronic component can be reliably placed at a predetermined position on the board surface without adversely affecting the board K and the mounting parts T. T can be attached.

H1 Effects of the Invention As is clear from the above explanation, the electronic component mounting apparatus according to the present invention detects the amount of warpage on the surface of the board by using a non-contact measuring device to detect the amount of warpage of the board being transferred to the component mounting position. and controlling the descending stroke of the suction nozzle so that the bottom of the component is located at a predetermined position on the board surface by calculating the height of the part to be mounted, and mounting the electronic component on the board surface using the suction nozzle. Because it is possible to
When attaching the electronic component to the board, it is possible to perform reliable positioning without applying unnecessary impact to the board or the electronic component.

...Rotary head...Sensor 2...Nozzle stroke variable actuator 4...
Length measurement unit 5...CPU

[Brief explanation of drawings]

FIG. 1 is an external perspective view showing an electronic component mounting device according to the present invention, FIG. 2 is a block circuit diagram showing a control circuit of the device, and FIG. 3A is the amount of warpage of a board measured by a non-contact measuring device in this device FIG. 3B is a diagram showing the NC data obtained from the above measurement. FIG. Figure 5 is a plan view of the station. FIG. 6 is a sectional view of a main part showing how an electronic component is mounted on a board using a suction nozzle of a conventional electronic component mounting apparatus, and FIG. 7 is a sectional view of a main part showing a conventional vacuum type board holder. 2...Suction nozzle

Claims (1)

[Scope of Claims] A non-contact method that measures the amount of warpage over the entire area of the board that is driven and held by a board transfer means that transports the board to a component mounting position and a measuring device driving and holding unit that has been transferred to the component mounting position. It has a measuring device and a suction nozzle that suction-holds electronic components to be attached to the board and moves them to a predetermined position on the board.The non-contact measuring device detects the amount of warpage on the board surface and calculates the amount of warpage. and the height of the component to control the downward stroke of the suction nozzle so that the bottom surface of the component is located at a predetermined position on the surface of the board.